CN2421796Y - Electronic ballast for safety voltage power-supplying cold light source gas discharge lamp - Google Patents

Abstract

The invention provides an electronic ballast for safe power supply cold light source gas discharge lamp, which is mainly output by a high-frequency inverter circuit and boosted by a high-frequency transformer to supply the ballast circuit with power for the lamp. The lighting circuit takes the voltage at both ends of the lamp and doubles the voltage After the circuit is boosted, the bidirectional diode is triggered. The bidirectional diode is connected in series with the inductance coil. The inductance coil is wound on the iron core of the transformer or the iron core of the ballast. The inductance coil has a pulse passing through it, which is connected to the secondary side of the transformer to make the two ends of the lamp reach the discharge voltage. After lighting, the voltage at both ends of the lamp decreases, the bidirectional diodes are cut off, and the lighting circuit does not work.

Description

Safe voltage power supply cold light source gas discharge lamp electronic ballast

The invention relates to an electronic ballast for a cold light source gas discharge lamp powered by a safe voltage, and belongs to the technical field of cold light source gas discharge lamp power supplies. At present, due to its good spectral characteristics and high luminous efficiency, cold light source gas discharge lamps are widely used in outdoor occasions such as roads, squares, tunnels, ports and station wharves. With the improvement of manufacturing technology, it has begun to expand to indoor applications in recent years. Electronic ballasts are an essential component to enable these lamps to take advantage of their energy savings. In ordinary occasions (we call it traditional) applications, the power supply voltage is AC 110V or AC 220V, which is mainly used in outdoor public places. Electronic ballasts replace inductive ballasts, but only have a history of 1 to 2 years. Lamps powered by low power supply voltage (AC/DC 12V ~ 48V) are widely used because they are more in line with the safety regulations for household use. However, since the lighting voltage of such lights is generally above 3000V, how to realize lighting in a simple and reliable way more difficult.

The object of the present invention is to design a lighting circuit for a cold light source gas discharge lamp working under low power supply voltage.

The technical solution of the present invention is achieved in this way, the ballast mainly includes a high-frequency inverter circuit, a high-frequency transformer, a ballast circuit and a lighting circuit, the high-frequency inverter circuit outputs to the primary side of the high-frequency transformer 4, and the high-frequency transformer The auxiliary side is connected to the ballast circuit, which mainly includes a capacitor 6 and a ballast 7 connected in series in the circuit, and a gas discharge lamp 8 connected in series in the circuit, and its characteristic is that the lighting circuit includes a double voltage boosted by taking the voltage at both ends of the lamp 8 circuit, the output of the voltage doubler circuit contacts the trigger circuit, and there is an inductance coil 14 in the trigger circuit, and the inductance coil 14 has a coupling relationship with the high-frequency transformer 4 or the ballast inductance 7 . That is, the inductance 14 shares the iron core with the high-frequency transformer 4 or the ballast 7 and conforms to the coupling relationship.

The above-mentioned voltage doubling circuit is 2 to 5 times the voltage.

The above gas discharge lamp electronic ballast is characterized in that the trigger circuit includes a charging capacitor 12, which passes through a current limiting resistor and is at the output end of the voltage doubler circuit.

The above-mentioned gas discharge lamp is characterized in that the switch element 13 in the trigger circuit is a bidirectional trigger diode.

The advantages of the present invention are: the lighting circuit is boosted by a voltage doubling method on the high frequency side, the required capacitance is small, the circuit is simple, and the loss is small. When the charging capacitance reaches the breakdown voltage of the bidirectional trigger diode, the trigger current flows through the inductor The coil 14 is coupled through a high-frequency transformer or ballast core, so that the secondary side of the transformer or the ballast coil induces a high voltage, so that the gas discharge lamp can obtain a lighting voltage above 3000V. Since the control signal is taken from both ends of the lamp, When the lamp is lit, the voltage at both ends drops from the no-load high voltage to the working voltage, the switch tube is automatically turned off, and the lighting circuit does not work. This scheme skillfully solves the lighting problem of cold light source gas discharge lamp under the condition of low-voltage power supply. The circuit is simple, reliable, stable and low power consumption. It is widely used in the fields of high-pressure sodium lamps, low-pressure sodium lamps, metal halide lamps and other gas discharge lamps, and complies with safety regulations.

The accompanying drawings are described below: Fig. 1 is a logical block diagram of the present invention, Fig. 2 is an embodiment of inductance 14 coupled with a high-frequency transformer, Fig. 3 is an embodiment of inductance 14 coupled with a ballast, among the figures: 1 2 is the power transistor for push-pull, 3 is the middle tap of the primary side of the high-frequency transformer, 4 is the high-frequency transformer, 5 is the side coil of the transformer, 6 is the resonant capacitor, 7 is the ballast coil, 8 Is a gas discharge lamp, 9 is a capacitor in the voltage doubling circuit, 10 is a diode in the voltage doubling circuit, 11 is a current limiting resistor, 12 is a charging capacitor; 13 is a bidirectional trigger diode; 14 is an induction coil.

Describe the embodiment of the present invention and working process below:

Accompanying drawing 2 is embodiment 1:

After the amplified positive and negative pulse signal 1 is sent to a pair of push-pull power transistors 2, a typical push-pull circuit is used to invert the current with a voltage of 12V-48V into an alternating current, and the secondary coil 5 of the transformer 4 to obtain the required frequency and voltage. When a reasonable parameter matching is achieved, the coils 5 and 7, the capacitor 6 and the lamp tube 8 reach resonance, so that the sodium lamp is in the state of the highest working efficiency.

Before the lamp is lit, the voltage at both ends of the lamp is usually above 100V. After it is lit, the voltage drops to about 50V. Therefore, the voltage signal is taken from both ends of the lamp, and the voltage doubler circuit composed of the capacitor 9 and the rectifier 10 is used. After the voltage is boosted, the capacitor 12 is charged through the resistance 11 line current, and when a certain voltage is reached, the bidirectional diode 13 is turned on, and a trigger pulse is sent to the coil 14, and the gas discharge lamp is activated by using the high voltage signal obtained in the secondary coil 5 of the transformer. 8 lights up. Obviously, when the lamp is lit, the voltage at both ends of the lamp tube drops by 1 times, and after the lamp is lit, it shows an obvious low-impedance state, which triggers the diode to cut off, and the high-voltage lighting signal no longer exists.

Accompanying drawing 3 is embodiment 2:

Embodiment 2 is basically the same as Embodiment 1, except that the ignition trigger coil 14 is not wound on the transformer 4 , but is wound on the iron core of the ballast 7 . The same effect as in Example 1 is achieved.

The above two figures only show the situation of 2 times the voltage, according to the need to increase the number of times, the number of voltage times, the selection of the breakdown voltage of the bidirectional trigger diode is related to the lighting voltage and the number of turns and ballast of the secondary side of the transformer The number of turns of the device and the number of turns of the inductance coil 14 are related, and can be adjusted mutually. The utility model selects 3-5 turns for the inductance coil, selects 240-300V for the breakdown voltage of the two-way diode, and selects 80-150 turns for the side of the transformer.

Claims (4)

1, a kind of electronic ballast for gas discharge lamp as cold light source powered by safe voltage, mainly comprise high-frequency inverter circuit, high frequency transformer, ballasting circuit and lamp circuit, high-frequency inverter circuit exports the former limit of high frequency transformer (4) to, high frequency transformer is paid the edge joint ballasting circuit, it mainly comprises the electric capacity (6) that is connected in the loop, ballast inductance (7), gaseous discharge lamp (8) is connected in the loop, it is characterized in that lamp circuit comprises gets the voltage-multiplying circuit that lamp (8) both end voltage is boosted, voltage-multiplying circuit output contact lamp circuits for triggering, inductance (14) is arranged in the circuits for triggering, and inductance (14) has lotus root to close relation with high frequency transformer (4) or ballast inductance (7).

2, electronic amperite of gas-discharge lamp according to claim 1 is characterized in that voltage-multiplying circuit is 2～5 multiplication of voltages.

3, electronic amperite of gas-discharge lamp according to claim 1 and 2, it is characterized in that circuits for triggering comprise charging capacitor (12), it is by current-limiting resistance and at the voltage-multiplying circuit output, switch element (13) be connected in parallel on capacitor (12) two ends after inductance (14) is connected.

4,, it is characterized in that the switch element (13) in the circuits for triggering is a bidirectional trigger diode according to claim 1 or 3 described electronic amperite of gas-discharge lamp.

Images